1. Field of the Invention
The present invention relates to a natural rubber product and a production method using whole plant, latex serum, proteins of fig tree(Ficus carica).
2. Description of the Prior Art
Natural rubber is a polymer composed of 320 to 35,000 isoprene molecules that are enzymatically linked in a head-to-tail configuration. A large number of plant species contain rubber, including Hevea brasiliensis, Parthenium argentatum (guayule) and Ficus elastica. Rubber is formed as a branch of the isoprenoid pathway in these plants. Proteins including rubber transferase and rubber elongation factor are required for sequential addition of isopentenyl pyrophosphate units to the growing polyisoprene chain to provide a high molecular weight polymer. In H. brasiliensis, Parthenium argentatum, and Ficus elastica, rubber transferase and rubber elongation factor are tightly associated with rubber particles where the chain elongation reaction occurs (Madhavan and Benedict, Plant Physiol. 75: 908-913 (1984); Light and Dennis, J. Biol. Chem. 264: 18589-18597 (1989); Siler and Cornish, Phytochem. 32: 1097-1102 (1993)).
Natural rubber (cis-1,4-polyisoprene) is a raw material of choice for heavy-duty tires and other industrial uses requiring elasticity, flexibility and resilience. Among more than 2,000 natural rubber producing plant species (Backhaus, Israel J. Botany 34: 283-293 (1985)), the Brazilian rubber tree (Hevea brasiliensis) is the only commercially viable source of natural rubber. However, diminishing acreage of rubber plantation and life-threatening latex allergy to Hevea rubber in hypersensitive individuals, coupled with increasing demand, make development of alternative rubber source imperative. In recent years, guayule (Parthenium argentatum Gray) which accumulates rubber in the parenchyma cells and contains high molecular weight rubber comparable to H. brasiliensis (Bowers, USDA Report (1990)) has attracted research interest as an additional source for natural rubber. P. argentatum Gray has been considered as a commercially viable rubber source for hypoallergenic latex (Cornish, U.S. Pat. Nos. 5,717,050; 5,580,942). However, guayule has limitation as an alternative rubber crop due to slow volume growth and low abundance of rubber particles. Therefore, the search for an effective alternative rubber producing plants has continued. The present invention relates to the synthesis of natural rubber from alternative source of rubber plant.